Investments (Realized Investment Gains Losses Net) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	$ 1,636		$ (5,206)		$ (1,441)
Fixed Maturities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	1,194		(93)		(37)
Equity Securities [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	512		444		24
Commercial Mortgage Loans [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	110		79		94
Real Estate Investment [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	(5)		2		(20)
Equity Method Investments [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	(15)		34		(2)
Derivative [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	(182)	[1]	(5,688)	[1]	(1,500)	[1]
Other Asset Types [Member]
Schedule Of Gain Loss On Investments [Line Items]
Total realized investment gains (losses), net	$ 22		$ 16		$ 0

[1] embedded derivatives as well as the offset of hedged items in qualifying effective hedge relationships prior to maturity or termination.